Apparatus with timed color change indication

ABSTRACT

An apparatus with time controlled color change indication comprises an apparatus includes a disposable, limited or restricted use product and an oxygen sensing color changeable dye disposed on a portion of the apparatus, the dye being translucent or having a first color upon application and for a defined time thereafter and the dye changing color after exposure to oxygen for the defined time. For example, a packaging for containing a product for human consumption has a portion with a color changeable dye disposed thereon. The dye changes color after being exposed to oxygen for a controlled and predetermined period of time indicating that the product for human consumption should no longer be consume or has decreased in freshness, quality of taste or potency.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is filed as continuation in part of Ser. No.13/688,550, which was filed Nov. 29, 2012, which is a divisional of U.S.patent application Ser. No. 12/504,107, which was filed Jul. 16, 2009,which is a continuation of U.S. patent application Ser. No. 11/607,298,which was filed on Nov. 30, 2006. The entire text of the aforementionedapplications is incorporated herein by reference in its entirety.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[Not Applicable]

FIELD OF THE INVENTION

The present invention relates to a disposable, limited or restricted useproduct that can transmit contaminants, and disease to a person or causeinfection if reused or used beyond a recommended period of time and moreparticularly to such an apparatus with a portion having a colorchangeable dye that changes color after being exposed to oxygen for apredetermined period of time indicating that the device should no longerbe used.

The present application further relates to packaging for a product forhuman consumption wherein the product for human consumption can declinein freshness, quality of taste, and/or potency and/or can cause diseaseif consumed beyond a recommended period of time. More particularly thepresent application relates to such a packaging with a portion having acolor changeable dye that changes color after being exposed to apredetermined percentage of oxygen for a predetermined period of timeindicating that the product for human consumption should no longer beconsumed or has decreased in freshness, quality of taste or potency.

BACKGROUND OF THE INVENTION

Many products currently marketed and sold to consumers are designed forlimited use. These products are usually associated with a single event,a restricted time period or restricted access. There are many reasonsfor the need of single use or limited use products.

An example of a single use product is a disposable syringe. Instrumentcontamination and cross infection between patients is an ever presentconcern if the syringe is inadvertently reused. It is a particularconcern in some countries where repeated use of instruments is known totransmit serious diseases such as HIV and hepatitis. Medical andophthalmic devices that must be sterilized such as scalpels ortonometers (for the measurement of a patient's intraocular pressure)body piercing and tattooing instruments used on multiple clients alsogive cause for concern. Needles used in acupuncture offer anotherexample. Decontamination procedures or employment of single-use devicesare methods used to control cross infection, but they rely on personnelawareness, willingness to follow protocol, monitoring and documentation.

The limited use type of product is usually associated with goods thatshould be used for a restricted time period. One example of this type ofproduct is “daily wear” or disposable contact lenses. Contact lenses forrefractive correction or cosmetic purposes require suitable wear andcare regimes in order to maintain good eye health. Non-compliance on thepart of the patient, either through choice or due to lack of education,can injure the eye. Frequent replacement lenses are sometimes worn forlonger than recommended or they may be stored or cleanedinappropriately.

A number of patents have tried to address the requirements for singleuse, limited use, or restricted access products.

U.S. Pat. No. 3,899,295 describes the use of an indicator containing apH sensitive dye applied to the container of a product such as a medicalinstrument. The indicator displays a first color in a normal atmosphere,then following introduction of a basic atmosphere the sensor displays asecond color. The problem with this patent is that the indicator is notdisplaying information relating to the condition of the productcontained within the package. Since the indicator is not incorporatedwithin or fixed onto the product, the information given actually relatesto the container, not its contents. An additional problem with thispatent is that the basic atmosphere in which the product is stored ischlorine gas which is highly reactive to the materials that comprisemany of the products that one could imagine being supplied in a sterilepackage container, such as metal surgical instruments and manypharmaceutical compounds or drugs.

Similarly, U.S. Pat. No. 4,098,577 by the same inventor describes asimilar pH sensitive indicator and two different atmospheric conditions,however that invention describes the indicator change in the presence ofan acidic atmosphere. As described above, the indicator is notincorporated within or fixed onto the product, therefore the informationpresented by the indicator relates to the container, not its contents.

U.S. Pat. No. 4,526,752 presents a tamper resistant package with anindicator means. The invention describes a container which incorporatesan indicator within its structure to display information on whether acontainer has been previously opened. As with other patents, theindicator relates to the condition of the package and not the productcontained in the package.

U.S. Pat. No. 6,790,411 describes a solution based hydrogen peroxideindicator where the solution has a first color in normal atmosphericconditions, then following a sterilization process using hydrogenperoxide, the solution exhibits a second color. One will certainlyrecognize a problem with this technique by considering the case where apackage that has been sterilized with hydrogen peroxide, is subsequentlytampered with, punctured, or otherwise damaged and made non sterile,while the indicator still displays the sterile condition.

U.S. Pat. No. 6,851,808 describes an ophthalmic lens product with anattached indication means that provides the user information relating tothe products condition or previous use. The invention overcomes many ofthe problems with the previously described patents. However, since theindicator means described in the patent uses changes in the product'slight environment as the initiator for the use indication display, andsince variations exist in the lighting environment where the product isused, the use indication can present at a rate that is faster or slowerthan that which is optimally desired.

Many products currently marketed and sold to consumers are suppliedprepackaged where the packaging is intended to preserve the freshness ofthe product or in the case of medication, the potency of the contentwithin the packaging. These products are usually associated with asingle event, i.e., the contents remain fresh or potent until thepackaging is opened by the consumer.

An example of the importance of preservation of a packaged product is acold tablet or a food item. Medicinal potency or food spoilage and theexpense related to these issues are important to both consumers andmanufacturers. Pharmaceuticals, food stuff, and similar items arecommonly packaged in sealed plastic containers.

Atmospheric oxygen permeation through the plastic material of thecontainer negatively affects the freshness of the contents of manypackaged products. In the case of pharmaceuticals, oxygen absorptiondecreases potency. In the case of food products, oxygen absorption intothe packaged food makes the food taste stale.

A number of patents have tried to address the requirements for packagingenvironment condition:

U.S. Pat. No. 4,285,697 describes the use of a spoilage indicatorapplied to the food within a container. The indicator displays a colorindication in response to various gases generated by the spoiled food.The indicator must be in contact with the product within the packaging.This patent does not describe a means to display the possible range ofconditions about the packaged contents, such as good, acceptable or bad.

Similarly, U.S. Pat. No. 4,003,709 presents a method to indicate thedeterioration of food within a package by detecting CO₂. This indicatordoes not have the possibility to indicate a range of freshness of thecontents within the package.

U.S. Pat. No. 4,526,752 presents a tamper resistant package with anindicator means. The invention describes a container which incorporatesan indicator within its structure to display information on whether acontainer has been previously opened. As with other patents, theindicator relates to whether the package has been opened or not, and notthe condition of the un-opened package and its contents.

U.S. Pat. No. 6,790,411 describes a solution based hydrogen peroxideindicator where the solution has a first color in normal atmosphericconditions, and then following a sterilization process using hydrogenperoxide, the solution exhibits another color. A package that has beensterilized with hydrogen peroxide, is subsequently tampered with,punctured, or otherwise damaged and made non sterile, would stilldisplay an indication of sterile conditions with this type of indicator.

U.S. Pat. No. 8,241,918 describes a freshness indicator for beveragesusing electronic data means and comparing the data via a processing unitto previously stored freshness criteria. This method is complex andexpensive.

BRIEF SUMMARY OF THE INVENTION

In accordance with the present invention the disadvantages of priorlimited use or restricted use products that can harm a person ifimproperly used as discussed above have been overcome. A disposablelimited or restricted use apparatus in accordance with the presentinvention includes a color changeable portion wherein the time that thecolor change occurs is controlled so that it coincides to theapproximate time of the end of one use of a single use apparatus or tothe approximate expiration time for extended but limited or restricteduse apparatus.

More particularly, the apparatus of the present invention with colorchange indication of use or expiration includes a limited or restricteduse apparatus having a portion that comes in contact with bodily fluidsor tissue so as to be susceptible to the transmission of contaminants ordisease to a person or to cause infection or injury. A color changeabledye is disposed directly on a portion of the apparatus, the dye having afirst color upon immediate exposure to oxygen and for a predeterminedtime thereafter and the dye changing color after the predetermined timeto provide a warning indication that the apparatus should no longer beused.

In one embodiment of the present invention, the apparatus may be amedical device such as a disposable syringe wherein the predeterminedperiod of time prior to color change is approximately five minutes. Inanother embodiment, the medical device is a disposable scalpel and thepredetermined period of time before which the dye changes color isgreater than or equal to one-half hour and preferably one hour. In stillanother embodiment, the apparatus is an ophthalmic device such as adisposable tonometer and the predetermined period of time before thecolor change occurs is approximately ten minutes.

In accordance with a further feature of the invention, the position ofthe dye on the device may be such that the device becomes unusable afterthe color change occurs.

In accordance with another feature of the present invention, theapparatus is a contact lens that is intended to be worn by a user suchthat the lens has a peripheral area that extends beyond the pupil and/orthe iris of a user's eye when worn and wherein the contact lens isdisposable such that it is not intended to be used for more than apredetermined period of time. A color changeable dye is disposed on aportion of the peripheral area of the contact lens wherein the dye issomewhat translucent prior to use of the contact lens and the dyechanges to a visible color after the contact lens has been exposed tooxygen for a predetermined period of time indicating that the contactlens should no longer be used. Because the color change indication ofexpiration is in the periphery of the lens, it does not obstruct theoptical zone of the lens. As such, the lens can still be used withoutobstructing vision after the color change occurs. However, a user isdiscouraged from continuing to wear the expired contact lens since thecolor change indication is visible and apparent to others.

An apparatus including a disposable limited or restricted use product inaccordance with the present invention includes an oxygen sensing colorchangeable dye disposed on a portion of the apparatus, the dye beingtranslucent or having a first color upon application and for a definedtime thereafter and the dye changing color after exposure to oxygen forthe defined time.

The dye can comprise and indicator such as Methylene Blue or SafranineT. The dye can also include glucose, sodium hydroxide, Iron (II)carbonate, wax, methyl cellulose and/or acacia gum.

The dye can be printed on the restricted or limited use product. Therestricted or limited use product can be a medical device such as ascalpel, a syringe, or an ophthalmic lens. In another embodiment the dyeis disposed upon a product for human consumption such as a pill.

The apparatus can also be a packaging for a product for humanconsumption. The dye disposed on a portion of the packaging. Forexample, the dye can be disposed on an interior of the packaging so thatit is visible from an exterior of the packaging.

The product for human consumption can decrease in freshness, quality oftaste or potency after exposure to oxygen for a period of time. Thedefined time after which the dye changes color can be coordinated to beapproximately equal to the period of time after which the product forhuman consumption decreases in freshness, quality of taste or potency inorder to indicate freshness, quality of taste and potency to a potentialpurchaser.

The packaging can have a second oxygen sensing color changeable dyedisposed on it, the dye being translucent or having a first color uponapplication and for a second defined time thereafter and the dyechanging color after exposure to a second defined percentage of oxygenfor the second defined time. The packaging can further have at least oneother oxygen sensing color changeable dye disposed on it, the dye beingtranslucent or having a first color upon application and for at leastone other defined time thereafter and the dye changing color afterexposure to at least one other defined percentage of oxygen for the atleast one other defined time.

In one embodiment of the packaging with at least three dyes thereon, thefirst dye changes color after exposure to approximately 5% oxygen forapproximately 1 minute, said second dye changes color after exposure toapproximately 10 to 15% oxygen for approximately 1 minute and said otherdye changes color after exposure to approximately 20% oxygen forapproximately 1 minute. In another embodiment of the packaging with atleast three dyes thereon, the first dye changes color after exposure toapproximately 5% oxygen for approximately 1 minute, said second dyechanges color after exposure to approximately 10 to 15% oxygen forapproximately 10 minutes and said other dye changes color after exposureto approximately 20% oxygen for approximately 1 hour. In yet anotherembodiment of the packaging with at least three dyes thereon, the firstdye changes color after exposure to approximately 5% oxygen forapproximately 10 minutes, said second dye changes color after exposureto approximately 10 to 15% oxygen for approximately 10 minutes and saidother dye changes color after exposure to approximately 20% oxygen forapproximately 10 minutes. In yet another embodiment of the packagingwith at least three dyes thereon, the first dye changes color afterexposure to approximately 5% oxygen for approximately 1 hour, saidsecond dye changes color after exposure to approximately 10 to 15%oxygen for approximately 10 minutes and said other dye changes colorafter exposure to approximately 20% oxygen for approximately 1 minute.

The product for human consumption inside the packaging can also have anoxygen sensing color changeable dye disposed thereon, the dye beingtranslucent or having a first color upon application and for a definedtime thereafter and the dye changing color after exposure to atmosphericoxygen for the defined time.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of a syringe in accordance with oneembodiment of the present invention depicting the area of the colorchangeable dye overlying the graduated scale of the syringe;

FIG. 2 is a perspective view of the syringe of FIG. 1 depicting thesyringe after the timed color change occurs;

FIG. 3 is an illustration of an alternative placement of the dye on asyringe;

FIG. 4 is an illustration of the syringe of FIG. 3 with an expirationmessage printed with the color changeable dye which becomes visibleafter a predetermined period of time;

FIG. 5 is a perspective view of the syringe of FIG. 3 contained in apackage to prevent premature actuation of the color changeable dye;

FIG. 6 is a perspective view of a scalpel with the color changeable dyein accordance with another embodiment of the present invention;

FIG. 7 is a perspective view of the scalpel of FIG. 6 with a messageprinted with the color changeable dye which has become visible after apredetermined time;

FIG. 8 is a cross-sectional view of a tonometer contacting a user's eyeand having the color changeable dye disposed on a central area of thetonometer lens through which the clinician looks;

FIG. 9 is a cross-sectional view of the tonometer and eye of FIG. 8 withthe dye providing a color change indication that the tonometer should nolonger be used;

FIG. 10 is a cross-sectional view of a contact lens in accordance withanother embodiment of the present invention on a user's eye;

FIG. 11 is a front perspective view of the contact lens of FIG. 10 withthe dye in peripheral areas of the contact lens;

FIG. 12 is a front perspective view of the contact lens of FIG. 11depicting the dye after color change has occurred to indicate expirationof the lens;

FIG. 13 is an alternative embodiment of the contact lens of FIG. 11; and

FIG. 14 is a cross-sectional view of a package containing the contactlens of FIG. 11 to prevent premature color change.

FIG. 15 is a perspective view of a packaging in accordance with oneembodiment of the present application depicting the area of thesequential color changeable printed inside the packaging and observablethrough the closed packaging.

FIG. 16 is an illustration of an oxygen indicator scale showing thefreshness information of the inside of a closed packaging.

FIG. 17 is an illustration of a packaging of FIG. 1 depicting thepackaging and indicator scale after the first in the series of colorchange occurs.

FIG. 18 is an illustration of a packaging of FIG. 1 depicting thepackaging after the last in the series of color change occurs.

FIG. 19 is an illustration series showing the multi-step printing of theindication in text while the previous text message is blanked out by thenewly activated indicator.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, a color change indication on aproduct provides accurate information or a warning to a user of: prioruse of a single use product or instrument; a reminder that a limited useproduct has reached it's expiration time; or that a product that isrestricted for use has been tampered with. The warning indication isprovided by a dye that changes color in a time controlled manner whereinthe dye is disposed on the product itself by being either printed on theproduct or incorporated within the material forming a portion of theproduct. The product is then subsequently packaged to provide a sterileenvironment for the product or limited access thereto. The internalatmosphere of the package is an inert gas or a vacuum such that thepackage provides a sealed, substantially atmospheric oxygen freeenvironment for the product. When the package is subsequently opened andthe product is exposed to atmospheric oxygen, the dye disposed on theproduct will change from translucent or somewhat translucent, i.e. amilky white or “water white,” to a blue or red color after a period oftime that is controlled by the composition of the dye as discussed indetail below, and that is selected to correspond to the typical time fora single use of a product in the case of single use products or thatcorresponds to the expiration time of the product. The time at which thedye changes color can also be selected so as to indicate that theproduct may have been tampered with.

In accordance with one embodiment of the present invention, as shown inFIG. 1, a disposable syringe 10 includes a graduated scale 12 printedthereon so that the amount of liquid drawn into the syringe can beaccurately measured. In one embodiment, the color changeable dye 14 isprinted over the scale. In this embodiment, the dye is substantiallytranslucent so that the scale is clearly visible until the dye 14changes color, as depicted at 14′ in FIG. 2, after a predetermined timeassociated with the time of typical use of the single use disposablesyringe 10.

For single use disposable products where the dye is required to besubstantially translucent and wherein the dye is to change color afterexposure to oxygen after five to ten minutes, the dye solution may beformed as follows. Approximately 12 grams of glucose is added to 600 ccof distilled de-ionized water. Next, approximately 12 grams of sodiumhydroxide is added to the mixture. To this mixture is added 10 cc of aMethylene Blue solution prepared by mixing 0.1 gram of Methylene Blue in100 cc of ethanol where the ethanol evaporates in the drying process.Thereafter, 60 grams of methyl cellulose is added to the mixture.Alternatively, E414 acacia gum may be substituted for the methylcellulose. This dye solution will change from translucent to blue in ashort amount of time after the package is opened and the product onwhich the dye is disposed is exposed to oxygen. If the color changedesired is from substantially translucent to a red color, 10 cc of aSafranine T solution can be substituted for the Methylene Blue solution.The Safranine T solution is prepared by mixing 0.3 grams of Safranine Twith 10 ml of ethanol.

In order to delay the time at which the dye changes color upon exposureto oxygen, Iron (II) carbonate can be added to the above dye solution.For example, 0.1 grams of Iron (II) carbonate can be added to a 3 mlquantity of the above dye solution forms a dye that will change color toeither blue or red after approximately nine or ten minutes. Byincreasing or decreasing the amount of Iron (II) carbonate the time thatit takes for the color change to occur upon exposure to oxygen can berespectively increased or decreased. It is noted that, the addition ofthe Iron (II) carbonate will change the dye from being substantiallytranslucent to somewhat translucent or a faint, milky white known as“water white” wherein the translucency diminishes as more Iron (II)carbonate is added.

In a preferred embodiment of the disposable syringe, a dye is employedthat remains translucent or somewhat translucent for a period ofapproximately five minutes, the typical time of a single use of thedisposable syringe. In the embodiment of the syringe depicted in FIGS. 1and 2, because the dye is disposed over the graduated scale, when thetime controlled color change occurs, the graduated scale is no longerclearly visible so that the disposable syringe cannot be accidentallyreused. In this manner, the transmission of contaminants or disease fromone patient to another by an inadvertent reuse of the syringe isprevented.

In another embodiment of the present invention as depicted in FIGS. 3and 4, the dye is disposed on another area such as 18 of the disposablesyringe 10. The dye can be used as an ink to print a message on thedisposable product so that when the color change occurs the message,such as the word “USED,” becomes visible to the user as shown at 18′ inFIG. 4. The dye of the present invention dries quickly after placed onthe product. After it is dry, the product can be sterilized with anycommon, low temperature sterilization technique and then placed in asealed container or package 16, as depicted in FIG. 5, with an internalatmosphere of an inert gas or a vacuum. In the sealed, substantiallyatmospheric oxygen free package, the ink will remain translucent or“water white”. When the package is subsequently opened and the productis exposed to atmospheric oxygen, the dye disposed on the product willchange from substantially translucent or “water white” to blue or redafter five or ten minutes depending upon the amount of Iron (II)carbonate in the solution.

If it is desired that the color change takes substantially longer thanten minutes, for example, twelve to sixteen hours, 0.5 grams of Iron(II) carbonate is added to a 3 ml quantity of the dye solution insteadof 0.1 grams of Iron (II) carbonate. It is noted that the Iron (II)carbonate acts as an oxygen scavenger in the dye solution thatpreferentially absorbs oxygen, converting to Iron (III) carbonate. Whenthe Iron (II) carbonate is completely converted to Iron (III) carbonate,the oxygen in the environment reacts with the color changeable dye sothat the dye changes to blue or red and becomes visible.

In order to prevent the dye from changing color until an even longertime has passed, wax can be added to the dye solution. To provide acolor change indication on a product after approximately 1500 hours orabout two months, the oxygen diffusion rate through the dye solution canbe lowered or decreased by the addition of wax as follows. Specifically,when 0.3 cc of beeswax is added to a 3 ml quantity of the dye describedabove, the color change is delayed by approximately ten hours for avolume of dye of 0.01 mm3. This amount of dye can be used in an area ofapproximately 2 mm in height and 20 mm long on a product. With theaddition of 0.6 cc beeswax to the dye solution, the color change can bedelayed to approximately 100 hours. To further extend the time that ittakes for the color change to 1500 hours, 0.7 grams of Iron (II)carbonate can be added to the dye solution and wax mixture. It is notedthat if too much wax is added to the dye, the quality of printing textcan decrease.

In another embodiment of the present invention as depicted in FIG. 6, adisposable scalpel 24 has the dye 26 of the present invention disposedthereon in an area that will be clearly visible to the surgeon when thedye changes color. As depicted in FIG. 7, a warning message 28 may beprinted with the dye on the scalpel to inform the surgeon that thescalpel has been “USED” wherein the color change occurs after at leastone-half hour and preferably one hour after the scalpel is removed froma substantially oxygen free package or container as discussed above withrespect to the syringe. In this way, the surgeon is warned that thescalpel should not be inadvertently used again but should be disposedof.

An ophthalmic device that incorporates the present invention is depictedin FIGS. 8 and 9. Specifically, FIG. 8 illustrates a tonometer 29 thatis used in contact with a patient's eyes 30. In ophthalmology, variousprocedures require a lens or instrument that contacts a patient's eye. Atonometer is one such device which includes a lens 31 which, for adisposable tonometer, may be formed of optical quality acrylic, forexample. The lens 31 has a surface 33 through which a clinician viewsthe eye 30 when the tonometer 29 is mounted on a slit lamp. Thetonometer 29 also includes a holder 29 which is used to mount thetonometer onto the slit lamp. For a disposable tonometer, the holder 29can be formed of plastic for example. In accordance with one embodiment,the dye 32 of the present invention can be disposed on a central area ofthe lens 31 of the tonometer. Since the typical time of use of thedisposable tonometer 29 of the present invention is very short, the dye32 can be of a formulation that is substantially translucent and doesnot change color for approximately five to ten minutes. After that time,when the dye changes color to blue or red, the dye prevents inadvertentreuse of the disposable tonometer by blocking the visual path in thetonometer to the patient's eye. Thus, the inadvertent transmission ofcontaminants or diseases from one patient to another patient via contactof a reused ophthalmic device with the patient's eyes is prevented. Inanother embodiment of the present invention, the dye can be disposed toform a ring or other symbol on the surface 33 of the tonometer lens 31or the dye can be disposed on the holder of the tonometer 36.

A problem that has arisen in ophthalmology with refractive contact lensuse such as “daily wear” or “monthly wear” disposable contact lenses isthat the user of the contact lens does not dispose of the contact lensat the recommended time but wears the contact lens longer than they aresupposed to. This however can damage the eye. The contact lens of thepresent invention as depicted in FIGS. 10-14 overcomes this problem byproviding a visual indication on the contact lens itself that thecontact lens should be removed from the eye after the contact lens hasbeen worn for the prescribed amount of time.

As shown in FIG. 10, a refractive contact lens 40 is worn on a cornea 36of an eye 30. Light 44 entering the person's cornea is correctly focusedby the contact lens 13 onto the retina at a point 45. The clear opticalpath of the light 44 intersects the central portion of the contact lensin the optical zone 48 of the eye and or lens. The periphery 43 of thecontact lens 40 as shown in FIGS. 10-13, however extends beyond theoptical zone 48 of the user's eye such that when the contact lens isworn, the peripheral area of the contact lens extends beyond the pupiland/or iris of a user's eye so that it overlies the iris and/or thesclera.

In accordance with the present invention, the color changeable dye 46 asdescribed above is disposed on a portion of the peripheral area of thecontact lens. The formulation for the dye is preferably that whichdelays the color change of the dye for approximately twelve to sixteenhours, or longer, according to the longest time that the contact lensmanufacturer suggests that the contact lenses should be worn. Becausethe formulation for the dye for twelve to sixteen hours includes Iron(II) carbonate, prior to the color change, the dye is milky white or“water white”. However, when the dye is disposed in one or more areassuch as 46 and 47 in the periphery 43 of the contact lens 40, when thecontact lens is worn by the user the area in which the dye is placed onthe contact lens overlies the iris and/or the sclera and is not visibleto an observer. As discussed above for the other devices, the contactlens 40 should be placed in a substantially atmospheric oxygen freepackage 50 as shown in FIG. 14. A user of the contact lens 40 removesthe contact lens from the package for immediate use in the eye. Afterthe contact lens has been worn in the eye for the recommended time bythe manufacturer, the color change of the dye occurs as depicted in FIG.12 wherein, dark blue or dark red spots are clearly visible in theperiphery of the contact lens by an observer looking into the contactlens wearer's eye. As such, the contact lens wearer is encouraged toremove the contact lens from his eye and dispose of it as recommended.However, because the dye is disposed in the periphery of the contactlens outside of the optical zone 48, the dye, after it changes colordoes not impair the vision of the user. As such, in emergencies, thecontact lens can be continued to be worn after the color change occurswithout visual impairment. However, the user is discouraged from wearingthe lens beyond its recommended use time since the die spots or ringwill be readily apparent by anyone looking at the contact lens wearer'seye.

FIG. 13 illustrates another embodiment of the positioning of the dye toform portions of a ring or a continuous ring in the periphery 43 of thecontact lens outside the optical zone 48.

In accordance with another embodiment of the present invention, a colorchange indication on a packaging provides accurate information or awarning to a user: that a product for human consumption within thepackaging has reached its expiration time; that a product for humanconsumption has decreased in freshness, quality of taste or potency orthat a product for human consumption within the packaging has beentampered with. The warning indication is provided by a dye that changescolor in a time controlled manner wherein the dye is disposed on thepackaging by being either printed on the packaging or incorporatedwithin the material forming a portion of the packaging. The dye is safefor human consumption so that it can come into contact with the productfor human consumption without any health concerns. In an alternativeembodiment, the dye could be printed on the product for humanconsumption itself without any health concerns.

The dye can be disposed on the interior of the packaging while alsobeing visible from the exterior of the packaging. Disposing the dye onthe interior of the packaging allows the color changing dye to monitorthe environment inside the packaging where the product for humanconsumption is contained. Making the dye visible from the exterior ofthe packaging allows the user to determine the environment on theinterior of the packaging where the product for human consumption iscontained without opening the packaging. For example, a packaging of thepresent application could contain a food product on the interior of thepackaging. A portion of the food packaging could be a clear materialwith the color changeable dye located on the interior of the clearportion. The color changeable dye could then be viewed by the user fromthe exterior while measuring the environment on the interior with thefood product. FIG. 15 is a perspective view of a packaging in accordancewith one embodiment of the present invention depicting the area of thecolor changeable dye printed inside the packaging and observable throughthe closed packaging.

The product for human consumption is packaged into the packaging of thepresent application to provide a sterile environment for the productand/or limited access thereto. The internal environment of the unopenedpackaging has a certain percentage of oxygen (O₂) present. For examplethe internal environment of the unopened packaging could be the same asthe atmosphere which contains approximately 21% oxygen. Alternatively,the packaging could be “flood packaged” by pumping in other gases, e.g.carbon dioxide or inert gases, during packaging. A packaging that wasflood packaged would have an internal environment with less than 21%oxygen. For example, a flood packaged internal environment could contain15-20% oxygen, 10-15% oxygen, 5-10% oxygen or 1-5% oxygen. In anotherexample, the packaging could by packaged in a vacuum such that thepackaging provides an internal environment that is substantially oxygenfree or approximately 0% oxygen. When the flood packaging or vacuumpackaging is subsequently opened, the internal environment and theproduct for human consumption therein are exposed to atmospheric oxygenand the oxygen percentage will increase.

After the product for human consumption is exposed to a certainpercentage of oxygen for a certain period of time, the product for humanconsumption may reach its expiration or decrease in freshness, qualityof taste or potency of the product. The length of the period of timeafter which a product for human consumption reaches its expiration ordecreases in freshness, quality of taste, or potency varies depending onthe percentage of oxygen in the environment to which the product forhuman consumption is exposed. For example, a food product will reach itsexpiration or decreases in freshness or quality of taste more slowly ina closed packaging at 10% oxygen than in an open packaging at 21%oxygen. These specific times and oxygen levels are only an example andwould differ depending on the internal product. For example, coffee thatis exposed to oxygen decreases in freshness and quality of taste veryquickly whereas potato chips decrease in freshness and quality of tastemore slowly.

After the dye has been exposed to a certain percentage of oxygen for acertain period of time, the dye disposed on the packaging will changefrom translucent or somewhat translucent, i.e. a milky white or “waterwhite,” to a blue or red color after a period of time that is controlledby the composition of the dye as discussed in detail below. The timeafter which the dye changes color is selected to correspond to thelength of the period of time after which a product for human consumptionreaches its expiration or decreases in freshness, quality of taste, orpotency at a certain percentage of oxygen. For example, if a foodproduct is stored in a packaging with 10% oxygen and is known to expireor lose freshness or quality of taste after exposure to 10% oxygen fortwo weeks, the dye could be timed to change color after exposure to the10% oxygen environment for two weeks. A potential purchaser of theproduct could then see that the food was expired or lower in freshnessor quality of taste by looking at the colored dye. These specific timesand oxygen levels are only an example and could be changed to correspondto the internal product.

A dye will change at a different time when exposed to a differentpercentage of oxygen. This feature of the dye allows them to also beused to monitor the internal environment of the closed packaging. Forexample, a vacuum packed bag of coffee might maintain freshness andquality of taste in a substantially oxygen free environment for twoweeks but will lose freshness and quality of taste in a 10% oxygenenvironment within a week and in a 21% oxygen environment within a day.This could be used with a dye that take two weeks to change in an oxygenfree environment but only 1 week in a 10% oxygen environment and only 1day in a 21% oxygen environment. If the vacuum packaging is compromisedand the oxygen environment within the packaging changes, the dye wouldchange indicating the potential effect on the coffee to the potentialpurchaser. These specific times and oxygen levels are only an exampleand could be changed to correspond to the internal product.

Different compositions of dye can be disposed on the packaging in asequential arrangement so the dye changes at different times to indicatea freshness or potency level as the freshness, quality of taste orpotency changes. FIG. 16 is an illustration of an oxygen indicator scaleshowing the freshness, quality of taste or potency information of theproduct inside of the closed packaging. The oxygen indicator scale hasdifferent compositions of dye at the end of the scale that indicates“good” and the level that indicates “bad.” The dyes will change atdifferent times as the product's freshness, quality of taste or potencygoes from good to bad. FIG. 17 is an illustration of a disposablepackaging apparatus of FIG. 16 depicting the packaging and indicatorscale after the first in the series of color change occurs. FIG. 18 isan illustration of a disposable packaging apparatus of FIG. 16 depictingthe packaging after the last in the series of color change occurs.

As an example of the sequential indicator, a food product could begin todecline in freshness or quality of taste after two weeks in an internalenvironment of 10% oxygen and continue the decline in an internalenvironment of 10% oxygen until its expiration date at one month. Thedye at the “good” end of the scale could turn after two weeks, the dyeat the middle end of the scale could turn at three weeks and the dye atthe “bad” end of scale could turn at one month. This would indicate thelevel of freshness to the potential purchaser before they purchase andopen the product. These specific times and oxygen levels are only anexample and could be changed to correspond to the internal product.Other words or symbols could be used in this indicator scheme and morelevels of indication could be added.

In yet another embodiment of the invention the sequential dye indicatorsare printed on top of each other, and given that the indicator dye isrelatively transparent until activated, the dyes may be printed suchthat a text message appears indicating the conditions within thepackaging and that the previous message is blacked out by the newlyactivated indicator in the sequence. FIG. 19 is an illustration seriesshowing the multi-step printing of the indication in text while theprevious text message is blanked out by the newly activated indicator.

As an example of this sequential indicator, a food product could beginto decline in freshness or quality of taste after two weeks in aninternal environment of 10% oxygen and continue the decline in aninternal environment of 10% oxygen until its expiration date at onemonth. In this example, the term “good” could been written in a firstdye that changes almost immediately after the food product is placed inthe packaging at 10% oxygen or in a non-changing dye in the same coloras the indicating color of the color changing dye. A second dye whichchanges color after two weeks at 10% oxygen could be applied over the“good” indicator to black it out and the term “ok” could be written inthe next area of the scale in that same dye. Finally, a third dye whichchanges color after four weeks at 10% oxygen could be applied over the“ok” indicator to black it out and the term “bad” could be written inthe next area of the scale in the same dye. In this example, thepotential purchaser would see the “good” indicator for the first twoweeks when the product is freshest. That indicator would be blacked outafter those two weeks and the potential purchaser would see the “ok”indicator during the two weeks after that when the product is startingto decline in freshness but has not yet expired. That indicator would beblacked out after four weeks and the potential purchaser would see the“bad” indicator. These specific times and oxygen levels are only anexample and could be changed to correspond to the internal product.Other words or symbols could be used in this indicator scheme and morelevels of indication could be added.

The prior examples use a constant percentage of oxygen with thesequential indicators. However, the sequential indicators can also beused to monitor varying oxygen levels. For example, a product coulddecrease in freshness or quality of taste after exposure to 5% oxygenafter 1 minute, 10% oxygen after 1 minute and greater than 15% oxygenafter 1 minute. The product could be vacuum packaged to be substantiallyfree of oxygen. Dyes that change after exposure to 5% oxygen after 1minute, 10% oxygen after 1 minute and 20% oxygen after 1 minute could beused as the three dyes on the sequential indicator. If the environmentin the package reaches 5% oxygen the first dye will change after 1minute. If the environment in the package reaches approximately 10%oxygen the second dye will change after 1 minute. If the environment inthe package reaches 20% oxygen the third dye will change after 1 minute.Alternatively, these changes could each occur after 10 minutes. Thesespecific times and oxygen levels are only an example and could bechanged to correspond to the internal product. Other words or symbolscould be used in this indicator scheme and more levels of indicationcould be added.

As yet another example, a product could decrease in freshness or qualityof taste after exposure to 5% oxygen after 1 minute, 10 to 15% oxygenafter 10 minutes and 20% oxygen after 1 hour. The product could bevacuum packaged to be substantially free of oxygen. Dyes that changeafter exposure to 5% oxygen after 1 minute, 10 to 15% oxygen after 10minutes and 20% oxygen after 1 hour could be used as the three dyes onthe sequential indicator. If the environment in the package reaches 5%oxygen the first dye will change after a minute. If the environment inthe package reaches 10 to 15% oxygen the second dye will change after 10minutes. If the environment in the package reaches 20% oxygen the thirddye will change after one hour. As yet another example, a product coulddecrease in freshness or quality of taste after exposure to 5% oxygenafter 1 hour, 10 to 15% oxygen after 10 minutes and 20% oxygen after 1minute. The product could be vacuum packaged to be substantially free ofoxygen. Dyes that change after exposure to 5% oxygen after 1 hour, 10 to15% oxygen after 10 minutes and 20% oxygen after 1 minute could be usedas the three dyes on the sequential indicator. If the environment in thepackage reaches 5% oxygen the first dye will change after an hour. Ifthe environment in the package reaches 10 to 15% oxygen the second dyewill change after 10 minutes. If the environment in the package reaches20% oxygen the third dye will change after one minute. These specifictimes and oxygen levels are only an example and could be changed tocorrespond to the internal product. Other words or symbols could be usedin this indicator scheme and more levels of indication could be added.

For applications where the dye is required to be substantiallytranslucent and wherein the dye is to change color after exposure to 21%oxygen after approximately 5-10 minutes, the dye solution may be formedas follows. Approximately 12 grams of glucose is added to 600 cc ofdistilled de-ionized water. Next, approximately 12 grams of sodiumhydroxide is added to the mixture. To this mixture is added 10 cc of aMethylene Blue solution prepared by mixing 0.1 gram of Methylene Blue in100 cc of ethanol where the ethanol evaporates in the drying process.Thereafter, 60 grams of methyl cellulose is added to the mixture.Alternatively, E414 acacia gum may be substituted for the methylcellulose. This dye solution will change from translucent to blue in ashort amount of time after the packaging is opened and the product onwhich the dye is disposed is exposed to oxygen. If the color changedesired is from substantially translucent to a red color, 10 cc of aSafranine T solution can be substituted for the Methylene Blue solution.The Safranine T solution is prepared by mixing 0.3 grams of Safranine Twith 10 ml of ethanol.

In order to delay the time at which the dye changes color upon exposureto oxygen, Iron (II) carbonate can be added to the above dye solution.For example, 0.1 grams of Iron (II) carbonate can be added to a 3 mlquantity of the above dye solution forms a dye that will change color toeither blue or red after approximately 9-10 minutes of exposure to 21%oxygen. By increasing or decreasing the amount of Iron (II) carbonatethe time that it takes for the color change to occur upon exposure tooxygen can be respectively increased or decreased. It is noted that, theaddition of the Iron (II) carbonate will change the dye from beingsubstantially translucent to somewhat translucent or a faint, milkywhite known as “water white” wherein the translucency diminishes as moreIron (II) carbonate is added.

If it is desired that the color change takes substantially longer than10 minutes at 21% oxygen, for example, 12-16 hours at 21% oxygen, 0.5grams of Iron (II) carbonate is added to a 3 ml quantity of the dyesolution instead of 0.1 grams of Iron (II) carbonate. It is noted thatthe Iron (II) carbonate acts as an oxygen scavenger in the dye solutionthat preferentially absorbs oxygen, converting to Iron (III) carbonate.When the Iron (II) carbonate is completely converted to Iron (III)carbonate, the oxygen in the environment reacts with the colorchangeable dye so that the dye changes to blue or red and becomesvisible.

In order to prevent the dye from changing color until an even longertime has passed, wax can be added to the dye solution. To provide acolor change indication on a product after approximately 1500 hours at21% oxygen, the oxygen diffusion rate through the dye solution can belowered or decreased by the addition of wax as follows. Specifically,when 0.3 cc of beeswax is added to a 3 ml quantity of the dye describedabove, the color change is delayed by approximately ten hours at 21%oxygen for a volume of dye of 0.01 mm3. This amount of dye can be usedin an area of approximately 2 mm in height and 20 mm long on a product.With the addition of 0.6 cc beeswax to the dye solution, the colorchange can be delayed to approximately 100 hours at 21% oxygen. Tofurther extend the time that it takes for the color change toapproximately 1500 hours at 21% oxygen, 0.7 grams of Iron (II) carbonatecan be added to the dye solution and wax mixture. It is noted that iftoo much wax is added to the dye, the quality of printing text candecrease.

A person familiar with the present technology could calculate the timeat which the dyes discussed herein would change in the presence of adifferent percentage of oxygen.

The present invention has much wider applications than have beendescribed herein. For example, the dye of the present invention can beused on cosmetic applicators that are stored with the cosmetic itselfsuch as mascara or eyeliner. It has been found that although suchcosmetics include preservatives to slow the growth of bacteria that caninfect the eye, these preservatives have a limited life so thatreplacement of cosmetics is recommended by doctors every three to sixmonths. The cosmetics however do not have an expiration date on theproduct or the package. The dye of the present invention can be appliedto the handle of a mascara applicator or eyeliner applicator, forexample, so that a warning message becomes visible at the recommendedtime of replacement. As such a user is warned that the cosmetic shouldbe disposed of prior to the expiration of the preservative to preventeye infections. The present invention is also applicable to oralmedications such as pills wherein the dye is printed directly onto thepill and changes color from white or translucent to another darker coloror warning symbol when the environmental oxygen level around the pillchanges. If the pills are individually packaged, the color changeindication can occur quickly after opening the package so as to providea tamper indication. As another example, in markets where counterfeitpills are a problem the color changeable dyes of the present inventioncould be applied to the real pills. After exposure to atmospheric oxygenfor a predetermined period of time, the real pills would change colorbut counterfeits would not. Instructions could be included indicatingthat pills that do not change after exposure to atmospheric oxygen for apredetermined period of time should not be used. Alternatively, ifmultiple pills are contained in a bottle or the like, the color changeindication of the dye should be timed to coincide with the expiration ofthe pills. It is noted that in preparing the, Methylene Blue solution,instead of ethanol, another type of alcohol can be used wherein thealcohol evaporates on the pill in the drying process.

Many further modifications and variations of the present invention arepossible in light of the above teachings. Thus, it is to be understoodthat, within the scope of the appended claims, the invention may bepracticed otherwise than as described hereinabove.

1. An apparatus with time controlled color change indication comprising: an apparatus that includes a disposable, limited or restricted use product; an oxygen sensing color changeable dye disposed on a portion of the apparatus, the dye being translucent or having a first color upon application and for a defined time thereafter and the dye changing color after exposure to oxygen for the defined time.
 2. An apparatus as recited in claim 1 wherein the dye comprises at least Methylene Blue, glucose, and sodium hydroxide.
 3. An apparatus as recited in claim 1 wherein the dye comprises at least Safranine T, glucose and sodium hydroxide.
 4. An apparatus as recited in claim 1 wherein the dye comprises at least Methylene Blue, glucose, sodium hydroxide, and Iron (II) carbonate.
 5. An apparatus as recited in claim 1 wherein the dye comprises at least Safranine T, glucose, sodium hydroxide and Iron (II) carbonate.
 6. An apparatus as recited in claim 1 wherein the dye comprises at least Methylene Blue and wax.
 7. An apparatus as recited in claim 1 wherein the dye comprises at least Safranine T and wax.
 8. An apparatus as recited in claim 1 wherein the dye comprises at least Methylene Blue, wax and Iron (II) carbonate.
 9. An apparatus as recited in claim 1 wherein the dye comprises at least Safranine T, wax and Iron (II) carbonate.
 10. An apparatus as recited in claim 1 wherein the dye comprises at least glucose, sodium hydroxide, Methylene Blue or Safranine T, and methyl cellulose or acacia gum.
 11. An apparatus as recited in claim 1 wherein the dye further includes wax and Iron (II) carbonate.
 12. An apparatus as recited in claim 1 wherein the dye further includes wax.
 13. An apparatus as recited in claim 1 wherein the dye further includes Iron (II) carbonate.
 14. An apparatus as recited in claim 1 wherein the dye is printed on the limited use apparatus.
 15. An apparatus as recited in claim 14 wherein the disposable, limited or restricted use apparatus is a medical device.
 16. An apparatus as recited in claim 15 wherein the medical device is a scalpel.
 17. An apparatus as recited in claim 15 wherein the medical device is a syringe.
 18. An apparatus as recited in claim 15 wherein the medical device is an ophthalmic lens.
 19. An apparatus as recited in claim 1 wherein said apparatus is a packaging for a product for human consumption.
 20. An apparatus of claim 19 wherein the dye disposed on a portion of the packaging.
 21. A packaging as recited in claim 19 wherein the dye is disposed on an interior of the packaging and is visible from an exterior of the packaging.
 22. An apparatus as recited in claim 19 wherein the product for human consumption decreases in freshness, quality of taste or potency after exposure to oxygen for a period of time
 23. An apparatus as recited in claim 22 wherein the defined time after which the dye changes color is approximately equal to the period of time after which the product for human consumption decreases in freshness, quality of taste or potency.
 24. An apparatus as recited in claim 19 wherein dye changing color after exposure to a defined percentage of oxygen for the defined period of time.
 25. An apparatus as recited in claim 24 further comprising a second oxygen sensing color changeable dye disposed on a portion of the apparatus, the dye being translucent or having a first color upon application and for a second defined time thereafter and the dye changing color after exposure to a second defined percentage of oxygen for the second defined time.
 26. An apparatus as recited in claim 25 further comprising at least one other oxygen sensing color changeable dye disposed on a portion of the apparatus, the dye being translucent or having a first color upon application and for at least one other defined time thereafter and the dye changing color after exposure to at least one other defined percentage of oxygen for the at least one other defined time.
 27. An apparatus as recited in claim 26 wherein said first dye changes color after exposure to approximately 5% oxygen for approximately 1 minute, said second dye changes color after exposure to approximately 10 to 15% oxygen for approximately 1 minute and said other dye changes color after exposure to approximately 20% oxygen for approximately 1 minute.
 28. An apparatus as recited in claim 26 wherein said first dye changes color after exposure to approximately 5% oxygen for approximately 1 minute, said second dye changes color after exposure to approximately 10 to 15% oxygen for approximately 10 minutes and said other dye changes color after exposure to approximately 20% oxygen for approximately 1 hour.
 29. An apparatus as recited in claim 26 wherein said first dye changes color after exposure to approximately 5% oxygen for approximately 10 minutes, said second dye changes color after exposure to approximately 10 to 15% oxygen for approximately 10 minutes and said other dye changes color after exposure to approximately 20% oxygen for approximately 10 minutes.
 30. An apparatus as recited in claim 26 wherein said first dye changes color after exposure to approximately 5% oxygen for approximately 1 hour, said second dye changes color after exposure to approximately 10 to 15% oxygen for approximately 10 minutes and said other dye changes color after exposure to approximately 20% oxygen for approximately 1 minute.
 31. An apparatus as recited in claim 28 wherein the product for human consumption has an oxygen sensing color changeable dye disposed thereon, the dye being translucent or having a first color upon application and for a defined time thereafter and the dye changing color after exposure to atmospheric oxygen for the defined time.
 32. An apparatus as recited in claim 1 wherein said dye is disposed upon a product for human consumption.
 33. An apparatus as recited in claim 32 wherein said product for human consumption is a pill.
 34. An apparatus as recited in claim 32 wherein the product for human consumption decreases in freshness, quality of taste or potency after exposure to oxygen for a period of time
 35. An apparatus as recited in claim 34 wherein the defined time after which the dye changes color is approximately equal to the period of time after which the product for human consumption decreases in freshness, quality of taste or potency.
 36. An apparatus as recited in claim 32 wherein dye changing color after exposure to a defined percentage of oxygen for the defined period of time.
 37. An apparatus as recited in claim 33 wherein said dye changes after exposure to approximately 20% oxygen. 